1. Field of the Invention
The present invention relates generally to containers. For instance, the present invention relates to insulated cups for holding hot or cold beverages.
2. State of the Art
Containers, such as cups for holding liquids or other materials, have been prevalently used for many years. Particularly, disposable cups and containers are used throughout the food industry, homes, offices, work sites, the transportation industry, and in many other circumstances and environments. Disposable cups and containers are generally made of foam, paper, or plastic.
In general, cups for use as personal beverage carriers generally exhibit a “frustoconical” configuration consisting of a closed circular base, a conical wall that extends upward and tapers radially outward from the outer perimeter of the base, and an open, circular mouth or rim. Because frustoconical cups are wider at the top than at the bottom, they may be top-heavy and, therefore, may not be resistant to tipping when filled.
Cup or container instability may be of considerable concern in many environments, for instance, such as on trains, airplanes, or motor vehicles, where bumps may cause frustoconically shaped cups to tip and the contents to spill out. Instability may be of greater concern when serving hot liquids, and particularly, when very hot liquids are disposed within frustoconically shaped disposable cups.
In order to compensate for this instability and consequent risk, cups have been designed with wide bottoms and narrow tops. While these designs make the filled container bottom heavy, and stable, such products have very limited commercial feasibility, and are not practicable in the context of disposable cups and containers for the simple reason that they cannot be efficiently stacked for packing, shipping and storage. U.S. Pat. No. 4,412,644 to La Fever discloses a spill-resistant disposable paper cup having a wide bottom and narrow top, but requires that a lid or covering be adhesively affixed to the bottom opening.
Furthermore, insulating a beverage or food, either hot or cold, is generally a preferable characteristic for a cup or container. Some of the materials used to make conventional cups and containers, like polystyrene, are relatively good insulators. In contrast, plastic and paper may be relatively poor insulators, making them unsuitable for holding very hot or very cold liquids. However, even polystyrene cups, if thin-walled, may be unsuitable or uncomfortable when holding very hot liquids or may be structurally inadequate. Also, polystyrene is not easily recycled and is not biodegradable.
Cup liners, sleeves, and cup holders, which fit against and surround the outside wall of cups to better insulate paper and plastic cups and thin-walled foam cups or at least prevent burning of hands holding such cups, are well known and commercially available. For instance, U.S. Pat. No. 5,205,473 to Coffin, Sr. discloses a corrugated beverage holder sleeve that fits about a cup to provide insulation from the contents thereof.
Other cup and container configurations have provided a double wall for insulation or stability for use with a cup or container. U.S. Pat. No. 4,548,348 to Clements discloses an expanded base for preventing the spilling of a cup, as does U.S. Pat. No. 4,865,199 to Zimmer and U.S. Pat. No. 5,143,247 to Gavle. U.S. Pat. No. 6,562,270 to Gannon et al. discloses a combination disposable cup insulator/stabilizer. Also, U.S. Pat. Nos. 3,372,830 to Edwards, 3,612,346 to Schneider, 4,548,348 to Clements, 4,867,313 to Padovani all disclose double-walled containers and cups. In addition, U.S. Pat. No. 3,337,109 to Shumrak discloses a sleeve disposed about at least a portion of a cup for insulating and supporting thereof.
In addition, stacking of containers including a lid has also been of interest in the past. One particular concern is stacking individual cups as well as respective sleeves for holding such cups, which may be addressed by proper sizing and design to allow stacking capability. However, another concern may be stacking containers and cups that are assembled with lids or sleeve structures. Conventional stacking approaches have been configured so that an upper cup sits upon the lid of a lower cup, such as U.S. Pat. No. 2,429,958 to Liebmann, U.S. Pat. No. 3,598,271 to Danforth, and U.S. Pat. No. 3,384,265 to Frank. However, conventional approaches appear to have not addressed stacking of containers or cups having sleeve structures disposed thereabout.
As may also be appreciated, due to the widespread use of cups and containers, particularly disposable cups, it would be advantageous to provide a container providing relatively good insulative qualities, stability against tipping, or both. Also, it would be advantageous to provide improved containers, such as insulated containers, cups, and assemblies thereof that may be stacked with relative stability.